Artificial silk



UNITED STATES PATENT OFFICE.

ROBERT DENIS ANCE, or LIVRY, FRANCE, ASSIGNOR 0F ONE-HALF '10 cEcrLSHRAGER, or LONDON, ENGLAND.

ARTIFICIAL SILK.

Specification of Letters Patent.

Patented Nov. 29, 1921.

- Application filed April 1, 1913. Serial No. 758,245.

. (GRANTED UNDER THE PROVISIONS OF THE ACT OF MARCH 3, 1921, 41 STAT. L,1313.)

To all whom it may concern:

Be it known that I, ROBERT DENIS LANCE, a citizen of the FrenchRepublic, and a resident of Livry, Seine-et-Oise, France, 18 RueSaint-Claude, gentleman, have invented certain new and usefulImprovements in and Relating to Artificial Silk, (for which I have filedapplications in France April 9, 1912; in Germany April 13, 1912,) ofwhich the fol lowing is a complete specification.

It is known that viscose or nitro cellulose silks present the defect ofoffering less resistance in a dry state to Various influences andparticularly to water than natural silk.

This invention has for its object artificial viscose and nitro cellulosesilks of great strength and from which fabrics that can even be washedin boiling water can be formed.

The process of making the silk which forms the object of the inventionconsists mainly in adding to solutions of viscoseor nitro-cellulosemetallic resinates, in particular resinate of zinc or of magnesium or amixture of the twopresenting a very high fusion point and for obtaininga pliable final product the percentage of resinates in the solutionshould not preferably exceed 20%. This proportion of resinates can,however, be exceeded if highly oxidized siccative oils, stearin, elaidinor a mixture of these bodies be added to the mixtures of viscose orcellulose and resinate. If an excess of metallic resinates be employed'ahard product analogous to celluloid is obtained. It is known to mixnitro cellulose moistened with a solution of sulfuric acid withsiccative oils previously treated with sulfur chlorid. It has also beenproposed to add to the solution a solution of caoutchouc and cellulose.

All these ingredients, however, do not furnish a utilizable silk,strongwhen dry and when in a humid state. In accordance with the presentinvention such a silk is obtained by adding metallic resinates tocellulose esters such as a solution of viscose or of nitro cellulose andthen spinningthe mixture. From this point of view the novel process isalso differentiated from the known, process consisting in impregnatingthreads and fabrics for example with resinate of aluminum, a process bywhich the threads only receive an excessively thin layer of resinatesWhile when the resinates are incorporated in the solution, the threadmanufactured is completely impregnated with these resinates andconsequently forms a body whichis almost completely impermeable.

It is known that the fusion point of resins,

vbalsams and gum-resins is considerably raised by the addition of zincoxid or magnesium oxid.

For example, the addition of 4% of zinc oxid to a colophony brings itsfusion point from 70 to 125; 8% from 70 to 170 2. temperature whichenables it to withstand a heat of 100 without softening inamanner-harmful to the silk.

In a cold state, the resinates prevent the silk from being penetrated bywater and enable it to retain great strength. They render it proofagainst soap washing or washing with alkaline carbonates.

These metallic resinates can be added to solutions of viscose or ofnitro cellulose in any proportions; as however these resinates arehardening agents and consequently present the property of destroying theelasticity of manufactured products, they must not be employed inproportions which, generally speaking, exceed 20%, if it be desired topreserve adequate pliability in the final product.

If it be desired to use higher proportions and still obtain pliableproducts, it is necessary to add to the mixtures eithersiccative oilsthat have already been highly oxidized, or, and preferably, stearin orbetter still elaidin or a mixture of these three bodies.

, In increasing the proportion of resinates, especially if aluminumresinate be employed without employing in conjunction therewith theproducts previously referred to, bodies or the nature of celluloid aremanufactured and these bodies can replace celluloid in many of itsapplications.

The resinates are obtained in the following manner: The resins, the.balsams or the gum-resins, according to circumstances, or a mixture ofthese products is dissolved in carbon disullid or ether, according as itis desired to incorporate the resinate with viscose or with nitrocellulose, oxids or hydroxids of zinc or of magnesia or a mixture of thetwo substances are then added in the proper proportion for the productto he obtained, the whole being then agitated until solution takesplace.

The carbon disulfid containing the resinate or resinates serves, in theordinary way, for dissolving the alkali-celluloseg similarly theresinated ether mixed with alcohol, henzin or acetone serves to dissolvethe nitro diminish the co-mbustibility or the products obtained by meansof nitro cellulose and consequently of avoiding or reducing the denitration.

The spinning of solutions of resinated viscose takes place in the samebaths as ordinary viscose. Resinated collodion is spun in the air likeordinary collodion. For the preparation of the viscose with a view tothis manufacture, it is advantageous for obtaining alkali-cellulose tosubstitute an alcoholic soda lye for anaqueous lye. The reaction takesplace in the same manner and ntense more speedily; furthermore, thealkali-cellulose thus obtained dissolves more readily in the resinatedcarbon disulfid.

Apart from the advantages referred to above which are inherent in theproduct obtained by this novel process the employment of metallicresinates, particularly in the case of nitro cellulose silk, presentsthe advantage that the nitro cellulose is highly diluted by therelatively large quantity of" resinates and that its combustibility isgreatly diminished by reason of the small combustibility of the metallicresinates. As, on the other hand, the thread loses some of its tenacityowing to the denitration, the silk that is not denitrated or onlyincompletely denit-rated in accordance with the novel process,notwithstanding the small proportion oi nitro cellulose that itcontains, presents greater strength because the nitro cellulose of whichit is composed is firmer.

l/Vhat I claim is:

1. an artificial silk comprising a cellulose ester having a metallicresinate with a high fusion point, said resinate not exceeding 2. Anartificial silk comprising a cellulose ester, a metallic resinate havinga high fusion point, and a highly oxidized siccative oil.

lln testimony whereof l have hereunto placed my hand at Paris, France,this eleventh day of March 1913.

ROBERT DENJIS LANCE.

In the presence of two Witnesses:

Louis COQUILLAT, LUCIEN MENNINGER.

